<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div id="app">
      <button v-on:click="hello('helen')">点击事件</button>
      <button v-on:click="study">去学习</button>
      <button @click="study">去学习</button>
    </div>

    <script src="vue.js"></script>
    <script>
      new Vue({
        el: '#app',

        methods: {
          hello(username) {
            alert('hello ' + username)
          },

          study() {
            alert('day day up')
          },
        },
      })
    </script>
  </body>
</html>
